Get a flat top receiver - EOTech holographic mounts for M4/M16/AR15

there is inadequate support for the eotech while on agressive rifle course. The sight can be bumped out of zero. you may not notice until 100yd shot. The mount will work ok for range work. The first time you hit your sight/mount, check your zero. If this is your only option to mount a eotech or other red dot sight, save your money- buy a new flat top upper receiver and get a rigid mounting platform. Great Idea, but not functional.
Pros: allows co-witness of iron sights
Cons: not rigid enough

This review was written in the old system and had content requirements that are different than reviews written today.